The present invention relates to a free-wheeling safety switch which is used for controlling the connection of a power supply to a motor. In particular, the present invention relates to a safety which is intended for use on a child's ride-on vehicle.
A number of forms of child's ride-one vehicles are known. One such vehicle is described in U.S. Pat. No. 4,558,263, entitled ALL TERRAIN VEHICLE TOY WITH DYNAMIC BRAKING. A usual feature of such ride-on vehicles is the provision of a battery, an electric motor, and a switching mechanism which is used to connect the battery to the electric motor, thereby allowing the child who is operating the vehicle to cause the vehicle to stop or go. Additional features are provided, such as reversing switches and dynamic braking circuits. The vehicles are generally powered by six to eighteen volt batteries.
As may be expected when such electromotive force is used, there is a potential for the contacts of a switch to weld with the sudden application of current from a battery power source. In certain circumstances, it is possible that a switch may weld in an "on" position, which would prevent the motor on the vehicle from being switched "off", leading to a runaway condition. Such a condition, aside from being a potential safety hazard, may also scare the child operating the vehicle.
The switch of the invention is designed to overcome the problems heretofore associated with switching mechanisms for ride-on vehicles and to also provide a positive, deliberate short circuit through a fusible link in the event that a contact in the safety switch becomes welded.
Accordingly, it is an object of the invention to provide a safety switch which will be operable to break the connection between battery and a motor even if a switch contact has welded into a closed position.
Another object of the invention is to provide a safety switch having sequentially operated, multiple conductors therein.
Another object of the invention is to provide a safety switch which is compact, easy to manufacture, and which may be easily replaced in the event of a welded contact.
A further object of the invention is to provide a safety switch which includes a free-wheeling, intermediate position.
The free-wheeling safety switch of the invention is intended for controlling a power supply for a motor and includes a linked single-throw conductor and a double-throw conductor. The double-throw conductor includes a center pole, a first, normally-closed contact, and a second, normally-open contact. The double-throw conductor is switchable from a normally closed position to a switched position wherein the first contact is open and the second contact is closed. The single-throw conductor includes a pole and a contact which is switchable between a normally-off position and an on position. A fusible link is located between the center pole and the single throw pole. The link between the double-throw conductor and the single-throw conductor switches the conductors sequentially such that the double-throw conductor switches between its normally closed position and its switched position prior to the single-throw conductor shifting from its normally-off position to its on position. The single-throw conductor is switched from its on position to its off position before the double throw conductor switches to its normally closed position. The power supply is electrically connected to the motor only when the double-throw conductor is in its switched position and the single-throw conductor is in its on position.
These and other objects and advantages of the invention will become more fully apparent as the description which follows is read in conjunction with the drawings.